Patent GB-1273638-A (GB)
Title: Centrifuge chuck
IPC: B04B7/00
Filed: 1969-09-02
Abstract: 1,273,638. Centrifugal separator. CRYOGENIC TECHNOLOGY Inc. 2 Sept., 1969 [23 Sept., 1968], No. 43474/69. Heading B2P. [Also in Division F2] A chuck 12 for holding the rotor 10 of a centrifuge, Fig. 1, comprises a closure ring 45, Fig. 2, having an inwardly extending peripheral lip 46 terminating its upper edge; a chuck body 48 having an annular ring member 49 and a circular registry section 55 for centering the rotor 10; an elastomeric gripping ring 58 positioned between the lip 46 and the upper edge of ring member 49; and an annular array of springs 72 positioned between the chuck body 48 and a pressure-applying means 65 and adapted to force the lip 46 against the ring 58 whereby in the absence of external force applied to the springs 72, the ring 58 is distended inwardly to grip the surface of the rotor 10. The chuck body 48 is secured to a spindle 54 mounted in bearings 146, 147 and driven by a motor through belt 152 and pulley 150. The pressure-applying means 65 consists of a brake disc fastened to the lower end of closure ring 45. The brake disc 65 and the chuck body 48 are provided with holes 70 and 60 respectively for receiving guide pins 73 on which are located washer closure springs 72 which seat in wells 71 formed in the disc 65. Braking is achieved when a cam torque cap 81 which during rotation of the centrifuge motor rests on the upper edge of the chuck housing 24 is raised upwardly so that its braking surface 82 made of paper-filled phenolic laminate contacts the disc 25. The cap 81 is secured by screws 99 to brake cam 100 having differently inclined cam faces which are caused to co-operate with follower rollers 110 rotatable on shafts 111 pressed into holes drilled in housing 24 to raise or lower the cam 100 and hence to bring the cap 81 into or out of contact with the braking disc 65. Engagement of the differently inclined cam faces is obtained by rotating the cam torque cap 81 through a small angle clockwise or anticlockwise by means of a cable 95. Fig. 6, clamped to the cap 81 and to actuating levers 31, 35 pivotable on a shaft 38 mounted in fixed supports 34, Fig. 1. A ring 128 rotatable with the chuck body 48 carries ejector pins 130 which extend through holes 61 in the chuck body and are maintained by springs 131 in an unprojected state from the holes 61 until actuated by ejector cam 115. The cam 115 is splined at 105-120 to the brake cam 100 so that arcuate movement of the torque cam cap 81 also moves the ejector cam through a small angle to cause follower rollers 122 which are freely rotatable on shafts 123 to engage the desired cam face of the ejector cam. The cam 115 has its engaging surface 138 maintained out of contact with the bottom surface 139 of the pin ring 128 during centrifuge rotation by springs 135 extending between the cam torque cap 81 and the ring portion 136 of the cam 115. Two clamping arms 18, of which only one is shown in Figs. 1 and 7, are pivotable on support posts 19 and are swingable into and out of operating position to bring a feed and effluent tube assembly 20, 21 into and out of communication with the interior of the rotor 10. When each arm is swung into the operative position it is locked by a spring loaded plunger 175 engaging into a notch 166 in a collar 165 carried by the respective posts 19.